With the rapid development of display technology, a touch screen panel has become popular in the daily life. Currently, according to the operation principle, the touch screen panel can be divided into a resistive type, capacitive type, infrared type, surface acoustic wave type, electromagnetic type, oscillatory wave induction type, frustrated total internal reflection optical induction type, or the like.
In a personal identification system based on the touch screen panel, various recognition methods with aid of a fingerprint have been applied extensively. There are lots of designs for realizing fingerprint recognition. These fingerprint recognition devices generally comprise an insulating layer on thin film transistors (TFTs) and photosensitive members on the insulating layer. The photosensitive members are generally connected with a drain of the TFT through vias which penetrate insulating layer. Since the vias in the insulating layer are generally formed by a dry etching process, the surface of the drain is rough. This adversely affects the optical property of photosensitive members, and thus affects recognition effect of the fingerprint recognition device.